Chemistry ATP Tips

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Hi everyone! Hope everyone's having a good time studying. I've put up this thread to present tips from what I've learnt by doing past papers.

Firstly, Offer salah and pray to ALLAH (Swt). The most important thing.Secondly, Believe in yourself and be confident.Now for the actual tips.- Read each question carefully and underline/highlight important words/information.- When describing colour changes, read the question again, especially in the case of indicators, see that to what is the indicator being added to and what is bringing the colour change.- When describing observations, especially reactions with water/solutions, use the words; dissolves, vigorously reacts, colour changes/fades, precipitate forms, the beaker heats up. Do not just give a theoretical answer.- Four tables: Solubility of Salts, Tests for Anions, Tests for Cations and Test for Gases should be at your fingertips.- Giving answers to reading questions, if there is a measuring cylinder, make sure you read off the flat side of the meniscus. - Some common reagents that you should know:

-Do not round off values in titration (or mole) questions! If the value 0.00248 is coming, don't write 0.0025, it will bring about a greater error in the later parts.-The following colours of compounds are good to be known.

Group 1, 2 metals are white/silvery white. Group 3 metals are shiny grey. Their compounds are white and their solutions are colourless.

Zinc is a grey solid, its compounds are white.

Lead is a shiny bluish metal, Iron is a shiny blackish solid.

Iron (II) salts are green. Iron (III) salts are red-brown.

Chlorine is a green gas. Silver chloride and Lead chloride are white.

Bromine is a red-brown gas. Silver bromide and Lead bromide are cream coloured.

Iodide is a black solid. Its vapours are purple. Silver iodide and lead iodide are yellow.

Nitrogen dioxide is a brown gas. Sulphur and Phosphorous are Yellow solids with different flames.

- Remember important points of electrolysis, ESPECIALLY selective discharge in concentrated/dilute solutions. Remember that displacement and electrolysis are redox reactions.- Remember important equations such as:

- In identifying ions, remember, if transition metal is present, a coloured SOLUTION will be formed not a coloured COMPOUND.- Also, when giving the test for Nitrate ions, don't forget the heat, it carries one mark.- Use a sharp pencil and plot a clean, clear graph.- For describing presence of gases (after reaction), use words, effervescence and bubbling.- The heating is done in the fume cupboard to ensure that students are not exposed to the poisonous gas, nitrogen dioxide. The toxicity of the gas is the point to mention. (from markscheme).- Remember, only potassium, sodium, calcium react with water to form hydroxides, all the metals below (till copper) react with STEAM to form metal oxides.- Also, remember that sodium and potassium compounds are very stable that do not break down on heating (their hydroxides break down to oxides and hydrogen on heating though). - Finally, best of luck to everyone giving Chemistry tomorrow! The best tip is to solve past papers, there is still ample time left!

I request anyone seeing this thread to add anything they would like to advice others! Hope this helps you people! Please pray that we all get A*'s.
P.S. I'll add more things when I remember something.

Also this formula will help alot:
Concentration = mole OR mass/volume
REMEMBER to convert volume to dm3 or cm3 as per requirement.

Also when an ester is formed, the formula will be like this:
C2H5OH + C2C5COOH ---> H2O + C2H5COOC2H5, also written as C2H5COOHCH2CH3
Which means that the hydrogen of the carboxylic acid will react with the last OH of alcohol, and in pleace of the hydrogen put the alcohol without the OH.

Aluminum oxide is a drying agent.

Unless the curve is ACTUALLY smooth you will not get a correct value.

In electrolysis if you want to INCREASE the amount of the pure substance on the cathode, use an anode of the same metal. For example if you want more silver to be formed on cathode during electrolysis, use a silver nitrate solution and silver anode.